JP2002001273A - Method for treating ash containing heavy metals or the like - Google Patents
Method for treating ash containing heavy metals or the likeInfo
- Publication number
- JP2002001273A JP2002001273A JP2001115471A JP2001115471A JP2002001273A JP 2002001273 A JP2002001273 A JP 2002001273A JP 2001115471 A JP2001115471 A JP 2001115471A JP 2001115471 A JP2001115471 A JP 2001115471A JP 2002001273 A JP2002001273 A JP 2002001273A
- Authority
- JP
- Japan
- Prior art keywords
- solution
- heavy metals
- incineration ash
- ferrous sulfate
- containing heavy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、特に、下水汚泥焼却灰
からの重金属等の溶出を防止する、重金属等含有灰の処
理方法に関するものである。ここで、重金属等とは、
「土壌の汚染に係る環境基準について（環境庁告示第46
号）」の項目にあるものをさす。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating ash containing heavy metals and the like, which prevents leaching of heavy metals and the like from sewage sludge incineration ash. Here, heavy metals and the like
"About environmental standards related to soil pollution (Environment Agency Notification No. 46
No.)).
【０００２】[0002]
【従来の技術】下水は、生活排水や工場排水等から構成
され、それを処理することにより生成された汚泥の焼却
残渣である下水汚泥焼却灰中には、ヒ素・セレンといっ
た重金属等が含まれている。下水汚泥の建設資材利用の
適否は、溶出試験により判断される。現在の基準として
は、「土壌の汚染に係る環境基準について（環境庁告示
第46号）」が適用されていることが多い。2. Description of the Related Art Sewage is composed of domestic wastewater and industrial wastewater, and heavy metals such as arsenic and selenium are contained in sewage sludge incineration ash, which is the sludge incineration residue generated by treating it. ing. The suitability of using sewage sludge for construction materials is determined by a dissolution test. As the current standard, "Environmental standards for soil pollution (Notification No. 46 of the Environment Agency)" is often applied.
【０００３】そこで、従来は、焼却灰に焼成（レンガ・
タイル化）や溶融（スラグ化）といった高度な二次処理
を行うことで、溶出基準を満足させ、それら生成物を有
効利用していた。また、有害物質の中で特に注目されて
いるヒ素・セレンについては、アルカリ性側で溶解度が
低くなるという特性を利用し、焼却灰に消石灰等を添加
して溶出試験時のpHをアルカリ性にし、溶出値を抑制す
る方法も検討されている。[0003] Therefore, in the past, incineration ash was fired (with bricks and ash).
By performing advanced secondary treatments such as tile formation and melting (slag formation), the elution standard was satisfied and those products were effectively used. For arsenic and selenium, which are particularly attracting attention among harmful substances, make use of the property of low solubility on the alkaline side, add slaked lime etc. to incinerated ash to make the pH during the dissolution test alkaline, and dissolve it. Methods for suppressing the value are also being studied.
【０００４】[0004]
【発明が解決しようとする課題】焼成や溶融処理では、
揮発（分離）及びガラス化（固化）の作用で溶出を防止
しているが、コストが高いのが難点である。また、焼却
灰に消石灰等を添加する方法は、現在行われている、中
性溶液による溶出試験（環境庁告示第46号）では、溶出
基準を満足するが、将来導入が予想される酸性条件また
は酸性溶液からの溶出試験（CO２飽和法等）において
は、その基準値を満足できないことが考えられる。In the firing and melting processes,
Elution is prevented by the action of volatilization (separation) and vitrification (solidification), but the disadvantage is that the cost is high. In addition, the method of adding slaked lime etc. to incinerated ash satisfies the elution standard in the current elution test using a neutral solution (Notification No. 46 of the Environment Agency), but the acidic conditions expected to be introduced in the future Alternatively, in a dissolution test (e.g., CO2 saturation method) from an acidic solution, the reference value may not be satisfied.
【０００５】本発明の目的は、上記のような問題点を解
決し、簡易に能率よく、安いコストで、揮発やガラス化
のような抜本的な不溶化処理を行い、中性及び酸性溶液
下において溶出基準値をクリアできる方法を提供するこ
とにある。An object of the present invention is to solve the above-mentioned problems, to carry out a radical insolubilization treatment such as volatilization or vitrification simply and efficiently at a low cost, and to carry out the treatment under a neutral or acidic solution. An object of the present invention is to provide a method capable of clearing an elution standard value.
【０００６】[0006]
【課題を解決するための手段】本発明者等は、上記の課
題を解決すべく検討を重ねた結果、焼却灰に、２価鉄化
合物及び/または３価鉄化合物、もしくはそれらの硫酸
塩、特に硫酸第一鉄の溶液を添加混練した後加熱処理す
ることにより、焼却灰に含有されるヒ素・セレンといっ
た重金属等を不溶化できることを見出した。Means for Solving the Problems As a result of repeated studies to solve the above-mentioned problems, the present inventors have found that a ferrous compound and / or a trivalent iron compound, or a sulfate thereof, In particular, it has been found that heavy metals such as arsenic and selenium contained in incinerated ash can be insolubilized by adding and kneading a solution of ferrous sulfate, followed by heat treatment.
【０００７】原焼却灰のセレン溶出量が特に多い場合
は、硫酸第一鉄の溶液を添加混練した後加熱処理する方
法では、セレンの溶出を抑えられない場合がある。この
ときは硫酸アンモニウム、または硫酸アンモニウム及び
アンモニア溶液を添加混練して加熱処理した後、さらに
硫酸第一鉄の溶液を添加混練して加熱処理することによ
り、セレン溶出が多い焼却灰でも、焼却灰に含有される
ヒ素・セレンといった重金属等を不溶化できることを見
出した。In the case where the amount of selenium eluted from the raw incineration ash is particularly large, the method of adding and kneading a solution of ferrous sulfate, followed by heat treatment may not be able to suppress the elution of selenium in some cases. In this case, ammonium sulfate, or ammonium sulfate and ammonia solution are added and kneaded, followed by heat treatment.Furthermore, by adding and kneading a solution of ferrous sulfate and heating, incineration ash with a high elution of selenium is contained in the incineration ash. It has been found that heavy metals such as arsenic and selenium can be insolubilized.
【０００８】しかし硫酸第一鉄の溶液を添加混練した後
加熱処理する方法、あるいは硫酸アンモニウム、または
硫酸アンモニウム及びアンモニア溶液を添加混練して加
熱処理した後、さらに硫酸第一鉄の溶液を添加混練して
加熱処理する方法では、焼却灰に含有されるヒ素・セレ
ンを不溶化できても、原焼却灰性状によっては新たにカ
ドミウムの溶出が起こる場合がある。これは硫酸第一鉄
の溶液を焼却灰に添加混練することにより、焼却灰の溶
出試験溶液のpHが低下してしまったためである。そこで
硫酸第一鉄の溶液を添加混練して、放置した後加熱処理
するか、硫酸アンモニウム、または硫酸アンモニウム及
びアンモニア溶液を添加混練して加熱処理した後、さら
に硫酸第一鉄の溶液を添加混練して放置した後加熱処理
する方法により、放置処理を組み合わせない場合より焼
却灰の溶出試験溶液のpHを上げることができ、焼却灰に
含有されるヒ素・セレン・カドミウムといった重金属等
を不溶化できることを見出した。However, a method of adding and kneading a solution of ferrous sulfate, followed by heat treatment, or a method of adding and kneading ammonium sulfate, or an ammonium sulfate and ammonia solution and heating, and further adding and kneading a solution of ferrous sulfate. In the heat treatment method, even if arsenic and selenium contained in the incinerated ash can be insolubilized, cadmium may be newly eluted depending on the properties of the raw incinerated ash. This is because the pH of the incineration ash elution test solution was lowered by adding and kneading the ferrous sulfate solution to the incineration ash. Therefore, a solution of ferrous sulfate is added and kneaded, and heat treatment is performed after standing, or ammonium sulfate, or an ammonium sulfate and ammonia solution is added and kneaded, followed by heat treatment, and further a solution of ferrous sulfate is added and kneaded. It was found that the method of heat treatment after standing allows the pH of the incineration ash dissolution test solution to be increased as compared with the case where the leaving treatment is not combined, and insolubilizes heavy metals such as arsenic, selenium, and cadmium contained in the incineration ash. .
【０００９】焼却灰の溶出試験溶液のpHを上げる方法と
しては焼却灰にpH調整剤を添加する方法を組み合わせて
もよい。すなわち硫酸第一鉄の溶液を添加混練した後加
熱処理するか、あるいは硫酸第一鉄の溶液を添加混練し
て放置した後加熱処理するか、あるいは硫酸アンモニウ
ム、または硫酸アンモニウム及びアンモニア溶液を添加
混練して加熱処理した後さらに硫酸第一鉄の溶液を添加
混練して加熱処理するか、あるいは硫酸アンモニウム、
または硫酸アンモニウム及びアンモニア溶液を添加混練
して加熱処理した後さらに硫酸第一鉄の溶液を添加混練
して放置した後加熱処理したものに、pH調整剤を添加す
ることにより、焼却灰に含有されるヒ素・セレン・カド
ミウムといった重金属等を不溶化できることを見出し、
本発明を完成するに至った。[0009] As a method for increasing the pH of the dissolution test solution of the incinerated ash, a method of adding a pH adjuster to the incinerated ash may be combined. That is, heat treatment after adding and kneading the solution of ferrous sulfate, or heat treatment after adding and kneading the solution of ferrous sulfate, or heat-treating, or adding and kneading ammonium sulfate, or ammonium sulfate and ammonia solution After the heat treatment, a solution of ferrous sulfate is further added and kneaded for heat treatment, or ammonium sulfate,
Alternatively, ammonium sulfate and ammonia solutions are added and kneaded, and heat treatment is performed.Furthermore, a solution of ferrous sulfate is added and kneaded. He found that heavy metals such as arsenic, selenium and cadmium could be insolubilized,
The present invention has been completed.
【００１０】すなわち本発明は、ヒ素・セレンといった
重金属等含有灰に、硫酸第一鉄の溶液を添加混練した
後、加熱処理することを特徴とするものである。硫酸第
一鉄の溶液を添加混練して、放置した後加熱処理するこ
とを特徴とするものである。硫酸アンモニウム、または
硫酸アンモニウム及びアンモニアの溶液を添加混練して
加熱処理した後、さらに硫酸第一鉄の溶液を添加混練し
て加熱処理することを特徴とするものである。硫酸アン
モニウム、または硫酸アンモニウム及びアンモニアの溶
液を添加混練して加熱処理した後、さらに硫酸第一鉄の
溶液を添加混練して、放置した後、加熱処理することを
特徴とするものである。〜に記載した方法により処
理したものにpH調整剤を添加することを特徴とするもの
である。That is, the present invention is characterized in that a ferrous sulfate solution is added to ash containing heavy metals such as arsenic and selenium, kneaded, and then heat-treated. It is characterized in that a solution of ferrous sulfate is added, kneaded, heated, and then heat-treated. After adding and kneading ammonium sulfate, or a solution of ammonium sulfate and ammonia, and heating, a solution of ferrous sulfate is further added and kneaded, followed by heat treatment. It is characterized by adding and kneading ammonium sulfate or a solution of ammonium sulfate and ammonia and heat-treating, further adding and kneading a solution of ferrous sulfate, allowing the mixture to stand, and then heating. The method according to any one of the above, characterized in that a pH adjuster is added to the composition treated.
【００１１】[0011]
【発明の実施の形態】以下、本発明の実施の態様につい
て説明する。本発明で処理される焼却灰は、ヒ素・セレ
ンといった重金属等含有灰であれば特に限定されるもの
ではないが、特に、下水汚泥焼却灰を対象とする。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described. The incineration ash to be treated in the present invention is not particularly limited as long as it is an ash containing heavy metals such as arsenic and selenium, but is particularly intended for sewage sludge incineration ash.
【００１２】本発明では、焼却灰に添加する薬品として
硫酸第一鉄を特定し、使用する。硫酸第一鉄は、硫酸第
二鉄や塩化第一鉄のような鉄塩試薬よりも安価で、塩化
第二鉄のような腐食性がなく取り扱いが容易なことが特
徴となる。また硫酸第一鉄は水に対する溶解度が高いの
で、この溶液は焼却灰と均一な混合が可能となる。硫酸
第一鉄は、焼却灰中に均一に混合させるために、溶液の
状態で添加され、溶液は焼却灰100に対して30重量％添
加が好ましい。溶液の割合が少ないと焼却灰と硫酸第一
鉄との混練状態が不充分となり、ヒ素やセレンを充分に
不溶化できなくなることがあり、また、溶液の割合が多
すぎると、添加後の焼却灰が液状となり、その後の加熱
処理にコストがかかることになる。In the present invention, ferrous sulfate is specified and used as a chemical added to the incineration ash. Ferrous sulfate is characterized by being cheaper than iron salt reagents such as ferric sulfate and ferrous chloride, and being easy to handle without corrosiveness unlike ferric chloride. In addition, since ferrous sulfate has high solubility in water, this solution can be uniformly mixed with incineration ash. Ferrous sulfate is added in the form of a solution in order to uniformly mix it in the incineration ash, and the solution is preferably added at 30% by weight based on 100 incineration ash. If the proportion of the solution is small, the state of kneading of the incineration ash and ferrous sulfate is insufficient, and it may not be possible to sufficiently insolubilize arsenic or selenium.If the proportion of the solution is too large, the incineration ash after addition may be used. Becomes liquid, and the subsequent heat treatment is costly.
【００１３】本発明の方法においては、上記の硫酸第一
鉄溶液と焼却灰とを混練した後、これを加熱処理する。
添加率にもよるが、硫酸第一鉄を混練することにより、
溶出試験時のpHが酸性となる。溶出試験時pH値が２を下
回るとヒ素等の溶出が起こりやすくなるため、この場合
はpH値が２以上になるようにpH調整をする必要がある。
また、混練にあたっては、あらかじめ焼却灰に加湿する
ことができる。混練方式については特に限定するもので
はなく、この技術分野で用いられている混練方式が採用
できる。In the method of the present invention, the above-mentioned ferrous sulfate solution and incinerated ash are kneaded and then heat-treated.
Depending on the rate of addition, by kneading ferrous sulfate,
The pH during the dissolution test becomes acidic. If the pH value during the dissolution test is less than 2, arsenic or the like is likely to be eluted. In this case, it is necessary to adjust the pH so that the pH value becomes 2 or more.
In addition, in kneading, the incineration ash can be humidified in advance. The kneading method is not particularly limited, and a kneading method used in this technical field can be employed.
【００１４】焼却灰と硫酸第一鉄溶液との混練物の加熱
では、硫酸第一鉄溶液により供給された鉄は２価鉄から
３価鉄に酸化され、硫酸第一鉄は３価鉄の水酸化物塩と
なる。３価鉄の水酸化物は、陰イオン吸着能を有するた
め、ヒ素・セレンのオキソ酸であるヒ酸イオン、亜ヒ酸
イオン、セレン酸イオン、亜セレン酸イオン等の各化合
物を吸着する。以上のように、加熱処理では、鉄の酸化
とヒ素・セレンの吸着が連続して起こり、結果的にヒ素
とセレンが不溶化されることになる。加熱温度は、焼却
灰に対する硫酸第一鉄の添加割合が無水物としての添加
割合で0.5重量％以上のときに50〜450℃の範囲とするの
が効果的であるが、より効果の高い範囲は硫酸第一鉄の
添加割合が無水物としての添加割合で1.4〜2.9重量％の
ときに50〜400℃が好ましい。In the heating of the kneaded material of the incineration ash and the ferrous sulfate solution, iron supplied by the ferrous sulfate solution is oxidized from ferrous iron to ferric iron, and ferrous sulfate is converted to ferrous ferrous sulfate. It becomes a hydroxide salt. Since trivalent iron hydroxide has an anion adsorption ability, it adsorbs various compounds such as arsenic ion, arsenite ion, selenite ion and selenite ion which are oxo acids of arsenic and selenium. As described above, in the heat treatment, oxidation of iron and adsorption of arsenic / selenium occur continuously, and as a result, arsenic and selenium are insolubilized. It is effective to set the heating temperature in the range of 50 to 450 ° C. when the addition ratio of ferrous sulfate to the incineration ash is 0.5% by weight or more in terms of the addition ratio as an anhydride. When the addition ratio of ferrous sulfate is 1.4 to 2.9% by weight as an anhydride, the temperature is preferably 50 to 400 ° C.
【００１５】硫酸第一鉄添加後の放置期間は1日以上と
するのが効果的であるが、より効果の高い範囲は７日以
上が好ましい。また硫酸第一鉄の添加割合が無水物とし
ての添加割合で0.5重量％以上のときに、前処理として
の硫酸アンモニウム、または硫酸アンモニウム及びアン
モニアの焼却灰に対する添加割合を0.5重量％以上とす
るのが効果的であるが、より効果の高い範囲は、硫酸第
一鉄の添加割合が無水物としての添加割合で1.4〜2.9重
量％のときに、硫酸アンモニウムで３重量％以上、ある
いは硫酸アンモニウム＋アンモニアで1.5重量％以上＋
0.5重量％以上、が好ましい。前処理としての硫酸アン
モニウム、または硫酸アンモニウム及びアンモニア添加
後の加熱温度は、50〜450℃の範囲とするのが効果的で
あるが、より効果の高い範囲は150〜450℃が好ましい。
pH 調整剤を加える場合は、焼却灰の溶出試験溶液のpH
が5程度以上に調整できるものが好ましい。It is effective that the standing period after the addition of ferrous sulfate is 1 day or more, but a more effective range is preferably 7 days or more. In addition, when the addition ratio of ferrous sulfate is 0.5% by weight or more as an anhydride, it is effective to set the addition ratio of ammonium sulfate or ammonium sulfate and ammonia to incineration ash to 0.5% by weight or more as pretreatment. However, the more effective range is that when the addition ratio of ferrous sulfate is 1.4 to 2.9% by weight as an anhydride, 3% by weight or more of ammonium sulfate or 1.5% by weight of ammonium sulfate + ammonia. % Or more +
0.5% by weight or more is preferred. The heating temperature after the addition of ammonium sulfate or ammonium sulfate and ammonia as a pretreatment is effectively in the range of 50 to 450 ° C, but the more effective range is preferably 150 to 450 ° C.
When adding a pH adjuster, check the pH of the incineration ash dissolution test solution.
Is preferably about 5 or more.
【００１６】[0016]
【実施例】以下に実施例を挙げて本発明をさらに詳細に
説明するが、本発明はこれらの実施例になんら限定され
るものではない。EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
【００１７】実験例１ 硫酸第一鉄の添加率を様々に変えて、硫酸第一鉄溶液添
加＋加熱処理の効果を調べ、最適硫酸第一鉄（FeSO４）
添加率を検討した。Experimental Example 1 The effect of ferrous sulfate solution addition + heat treatment was examined by changing the addition rate of ferrous sulfate variously, and the optimum ferrous sulfate (FeSO4) was examined.
The addition rate was studied.
【００１８】実験条件と結果を表１に示す。Table 1 shows the experimental conditions and results.
【００１９】[0019]
【表１】 [Table 1]
【００２０】焼却灰に硫酸第一鉄を無水物として1.7重
量％添加し、200または400または600℃で加熱処理し
た。硫酸第一鉄を無水物として1.7重量％添加し、加熱
処理しないものを比較対象とした。1.7% by weight of ferrous sulfate as an anhydride was added to the incinerated ash, and heat treatment was performed at 200, 400 or 600 ° C. 1.7% by weight of ferrous sulfate was added as an anhydride, and a sample not subjected to heat treatment was used as a control.
【００２１】ヒ素・セレンは上記の硫酸第一鉄溶液添加
＋加熱処理のうち、硫酸第一鉄（無水物として）1.7重
量％添加＋200℃加熱処理において、0.01mg/Lの溶出量
となった。As for arsenic and selenium, the addition of ferrous sulfate (as an anhydride) of 1.7% by weight and the heating at 200 ° C. of the above-mentioned ferrous sulfate solution addition + heat treatment resulted in an elution amount of 0.01 mg / L. .
【００２２】実験例２ 実験例１では、焼却灰に硫酸第一鉄を無水物として1.7
重量％添加後200℃で加熱処理した結果、ヒ素・セレン
の溶出量を0.01mg/Lにすることができた。そこでこの方
法について、その他重金属等の溶出量の変化を調べた。EXPERIMENTAL EXAMPLE 2 In Experimental Example 1, ferrous sulfate was used as an anhydride in incinerated ash for 1.7%.
As a result of heat treatment at 200 ° C. after addition of the weight%, the elution amount of arsenic / selenium could be reduced to 0.01 mg / L. Therefore, this method was examined for changes in the elution amount of other heavy metals and the like.
【００２３】実験条件と結果を表２に示す。Table 2 shows the experimental conditions and results.
【００２４】[0024]
【表２】 [Table 2]
【００２５】焼却灰に硫酸第一鉄を無水物として1.7重
量％添加し、200℃で加熱処理した。処理前原灰を比較
対象とした。Ferrous sulfate (1.7% by weight as an anhydride) was added to the incinerated ash, and heat treatment was performed at 200 ° C. Raw ash before treatment was used for comparison.
【００２６】処理前原灰及び処理灰ともにヒ素・セレン
以外の溶出はなかった。ヒ素・セレンは上記の硫酸第一
鉄溶液添加＋加熱処理により、0.01mg/L未満の溶出量と
なった。There was no elution except for arsenic and selenium in both raw ash and ash before treatment. Arsenic and selenium had an elution amount of less than 0.01 mg / L by the addition of the ferrous sulfate solution and the heat treatment.
【００２７】実験例３ 実験例１および２では環境庁告示第46号の溶出試験方法
（中性溶液からの溶出）により試験を行い、硫酸第一鉄
溶液添加＋加熱処理によるヒ素・セレンの不溶化効果を
確認した。ここでは将来導入が予想されるCO２飽和法お
よびCO２連続法（酸性溶液からの溶出）により溶出試験
を行い、その処理の効果を検討した。Experimental Example 3 In Experimental Examples 1 and 2, a test was performed according to the dissolution test method (dissolution from a neutral solution) of No. 46 of the Notification of the Environment Agency, and the insolubilization of arsenic and selenium by adding a ferrous sulfate solution and heating. The effect was confirmed. Here, a dissolution test was performed by a CO2 saturation method and a CO2 continuous method (elution from an acidic solution), which are expected to be introduced in the future, and the effect of the treatment was examined.
【００２８】実験条件と結果を表３に示す。Table 3 shows the experimental conditions and results.
【００２９】[0029]
【表３】 [Table 3]
【００３０】焼却灰に硫酸第一鉄を無水物として2.8重
量％添加し、200℃で加熱処理をした。溶出試験はCO２
飽和法及びCO２連続法により行った。環境庁告示第46号
法を比較対象とした。2.8% by weight of ferrous sulfate as an anhydride was added to the incineration ash, and heat treatment was performed at 200 ° C. Dissolution test is CO2
This was performed by the saturation method and the CO2 continuous method. The Environment Agency Notification No. 46 method was used for comparison.
【００３１】ヒ素・セレンは上記の硫酸第一鉄溶液添加
＋加熱処理により、CO２連続法でも、0.01mg/L未満の溶
出量となった。The arsenic / selenium had an elution amount of less than 0.01 mg / L even in the CO2 continuous method due to the addition of the ferrous sulfate solution and the heat treatment.
【００３２】実験例４ 実験例１〜３とは異なる下水汚泥焼却灰を用いて、硫酸
第一鉄の添加率、放置期間、加熱温度を様々に変えて、
硫酸第一鉄溶液添加＋放置＋加熱処理の効果を調べ、最
適条件を検討した。また、硫酸アンモニウム、または硫
酸アンモニウム及びアンモニアの添加率、添加後の加熱
温度、硫酸第一鉄の添加率、添加後の加熱温度を様々に
変えて、硫酸アンモニウム、または硫酸アンモニウム及
びアンモニア溶液添加＋加熱＋硫酸第一鉄溶液添加＋加
熱処理の効果を調べ、最適条件を検討した。なお、比較
として硫酸第一鉄溶液添加＋加熱処理の検討結果も併せ
て示す。EXPERIMENTAL EXAMPLE 4 Using sewage sludge incineration ash different from those of Experimental Examples 1 to 3, the addition rate of ferrous sulfate, the standing period, and the heating temperature were variously changed.
The effect of the ferrous sulfate solution addition + standing + heat treatment was examined, and the optimal conditions were examined. The addition rate of ammonium sulfate, or the addition rate of ammonium sulfate and ammonia, the heating temperature after addition, the addition rate of ferrous sulfate, and the heating temperature after addition, are variously changed to add ammonium sulfate or ammonium sulfate and ammonia solution + heating + sulfuric acid. The effect of the addition of a ferrous solution + heat treatment was investigated, and the optimal conditions were examined. In addition, the examination result of the ferrous sulfate solution addition + heat treatment is also shown for comparison.
【００３３】実験条件と結果を表４に示す。Table 4 shows the experimental conditions and results.
【００３４】[0034]
【表４】 [Table 4]
【００３５】比較として示した硫酸第一鉄添加＋加熱処
理では、焼却灰に硫酸第一鉄を無水物として1.7または
2.8重量％添加後、200または400℃で加熱処理した。硫
酸第一鉄添加＋放置＋加熱処理については、焼却灰に硫
酸第一鉄を無水物として1.7または2.8重量％添加し、７
日放置した後、200または400℃で加熱処理した。硫酸ア
ンモニウム、または硫酸アンモニウム及びアンモニア添
加＋加熱＋硫酸第一鉄添加＋加熱処理では、焼却灰に硫
酸アンモニウムを３重量％、または硫酸アンモニウム＋
アンモニアを１＋0.5重量％添加し、200または400℃で
加熱、さらに硫酸第一鉄を無水物として1.7重量％添加
し、200℃で加熱処理した。In the case of ferrous sulfate addition and heat treatment shown as a comparison, incinerated ash was converted to anhydrous ferrous sulfate of 1.7 or 1.7%.
After adding 2.8% by weight, heat treatment was performed at 200 or 400 ° C. For ferrous sulfate addition + standing + heat treatment, 1.7 or 2.8% by weight of ferrous sulfate as an anhydride was added to incinerated ash, and
After standing for a day, it was heat-treated at 200 or 400 ° C. In ammonium sulfate or ammonium sulfate and ammonia addition + heating + ferrous sulfate addition + heat treatment, 3% by weight of ammonium sulfate or ammonium sulfate +
Ammonia was added at 1 + 0.5% by weight, heated at 200 or 400 ° C., and ferrous sulfate as an anhydride was added at 1.7% by weight, followed by heat treatment at 200 ° C.
【００３６】硫酸第一鉄添加＋加熱処理では、ヒ素・セ
レンは溶出量を0.01mg/L未満にできていたが、カドミウ
ムが0.01mg/Lを超える溶出が見られる場合があった。し
かし硫酸第一鉄添加＋放置＋加熱処理、あるいは硫酸ア
ンモニウム、または硫酸アンモニウム及びアンモニア添
加＋加熱＋硫酸第一鉄添加＋加熱処理により、ヒ素・セ
レン・カドミウムのいずれも0.01mg/L未満の溶出量とな
った。In the case of adding ferrous sulfate and heat treatment, the elution amount of arsenic / selenium was reduced to less than 0.01 mg / L, but elution of cadmium exceeding 0.01 mg / L was observed in some cases. However, with the addition of ferrous sulfate + standing + heat treatment, or the addition of ammonium sulfate, or ammonium sulfate and ammonia + heating + ferrous sulfate addition + heat treatment, all of the arsenic, selenium and cadmium could be eluted at less than 0.01 mg / L. became.
【００３７】実験例５ 硫酸アンモニウム、または硫酸アンモニウム及びアンモ
ニア添加＋加熱＋硫酸第一鉄添加＋加熱処理について、
硫酸第一鉄溶液添加後に放置を組み合わせた硫酸アンモ
ニウム、または硫酸アンモニウム及びアンモニア添加＋
加熱＋硫酸第一鉄添加＋放置＋加熱処理と、後工程にpH
調整を行った各処理の効果を調べた。EXPERIMENTAL EXAMPLE 5 Addition of ammonium sulfate or ammonium sulfate and ammonia + heating + ferrous sulfate + heating treatment
Add ammonium sulfate or ammonium sulfate and ammonia combined with leaving after adding ferrous sulfate solution +
Heating + ferrous sulfate addition + standing + heat treatment and pH
The effect of each adjusted treatment was examined.
【００３８】実験条件と結果を表５に示す。The experimental conditions and results are shown in Table 5.
【００３９】[0039]
【表５】 [Table 5]
【００４０】硫酸アンモニウム、または硫酸アンモニウ
ム及びアンモニア添加＋加熱＋硫酸第一鉄添加＋放置＋
加熱処理では、焼却灰に硫酸アンモニウムを３重量％添
加し、200℃で加熱、さらに硫酸第一鉄を無水物として
1.7重量％添加し、７日放置した後、200℃で加熱処理し
た。各処理については、硫酸第一鉄添加＋加熱もしくは
硫酸第一鉄添加＋放置＋加熱後、溶出試験溶液のpHが5
となるようにpH調整剤を添加処理した。Addition of ammonium sulfate or ammonium sulfate and ammonia + heating + ferrous sulfate addition + standing +
In the heat treatment, 3% by weight of ammonium sulfate is added to the incineration ash, heated at 200 ° C., and ferrous sulfate is converted to an anhydride.
After adding 1.7% by weight and leaving it to stand for 7 days, it was heated at 200 ° C. For each treatment, after the addition of ferrous sulfate + heating or the addition of ferrous sulfate + standing + heating, the pH of the dissolution test solution was 5
PH adjuster was added so that
【００４１】ヒ素・セレン・カドミウムは、上記の硫酸
アンモニウム、または硫酸アンモニウム及びアンモニア
溶液添加＋加熱＋硫酸第一鉄溶液添加＋放置＋加熱処
理、あるいは各処理＋pH調整剤添加処理により、0.01mg
/L未満の溶出量となった。Arsenic, selenium, and cadmium can be added in an amount of 0.01 mg by adding the above ammonium sulfate or ammonium sulfate and ammonia solution + heating + ferrous sulfate solution + standing + heating treatment, or each treatment + adding a pH adjuster.
The elution amount was less than / L.
【００４２】[0042]
【発明の効果】本発明方法によれば、特に、下水汚泥焼
却灰の処理において、含有灰中のヒ素・セレンといった
重金属等を容易に効率よく不溶化でき、環境庁告示第46
号法（中性溶液からの溶出）でも、CO２飽和法及びCO２
連続法（酸性溶液からの溶出）でも、土壌の汚染に係る
環境基準値を満足できる。According to the method of the present invention, especially in the treatment of sewage sludge incineration ash, heavy metals such as arsenic and selenium in the ash contained can be easily and efficiently insolubilized.
Method (elution from neutral solution), CO2 saturation method and CO2
The continuous method (elution from acidic solution) can also satisfy the environmental standard value related to soil contamination.
【００４３】したがって、処理灰を50〜450℃の温度間
で、製品化する場合においては、無害な原料として、処
理灰をそのまま広く利用できる。また、地下水に直接触
れても溶出がなく安全であることから、直接土壌に触れ
る用途（土木資材）にも利用でき、仮に酸性雨が降った
場合でも安全性に問題はない。Therefore, when the treated ash is commercialized at a temperature of 50 to 450 ° C., the treated ash can be widely used as a harmless raw material. In addition, since it is safe because there is no elution even when it comes into direct contact with groundwater, it can be used for applications that directly touch the soil (civil engineering materials), and there is no problem in safety even if acid rain falls.
【００４４】そして、設備費、ランニングコストが安価
であり、特に、加熱処理においては既設焼却施設の予熱
空気（約600℃）の一部等を利用して実施できるので、
経済性に優れている。The equipment cost and running cost are low, and the heat treatment can be performed by using a part of the preheated air (about 600 ° C.) of the existing incineration facility.
Excellent economy.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 林 雅樹 東京都中央区日本橋室町３−１−３ 株式 会社クボタ東京本社内 (72)発明者 清水 洋治 東京都新宿区西新宿二丁目８番１号 東京 都下水道局内 (72)発明者 上野 孝司 東京都新宿区西新宿二丁目８番１号 東京 都下水道局内 Ｆターム(参考） 4D004 AA36 AB03 CA15 CA22 CA34 CA35 CC06 DA03 DA06 DA10 DA20 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaki Hayashi 3-1-3, Nihonbashi Muromachi, Chuo-ku, Tokyo Kubota Tokyo Head Office (72) Inventor Yoji Shimizu 2-2-1 Nishishinjuku, Shinjuku-ku, Tokyo Tokyo Metropolitan Sewerage Bureau (72) Inventor Takashi Ueno 2-8-1, Nishishinjuku, Shinjuku-ku, Tokyo Tokyo Metropolitan Sewerage Bureau F-term (reference) 4D004 AA36 AB03 CA15 CA22 CA34 CA35 CC06 DA03 DA06 DA10 DA20
Claims (10)
水汚泥焼却灰に添加、混練した後加熱処理することを特
徴とする、重金属等含有灰の処理方法。1. A method for treating ash containing heavy metals and the like, comprising adding a solution of ferrous sulfate to sewage sludge incineration ash containing heavy metals and the like, kneading the mixture, and heating the mixture.
酸第一鉄の溶液を添加混練して、放置した後加熱処理す
ることを特徴とする、重金属等含有灰の処理方法。2. A method for treating ash containing heavy metals and the like, comprising adding a solution of ferrous sulfate to sewage sludge incineration ash containing heavy metals and the like, kneading the mixture, leaving the mixture to stand, and then heating.
酸アンモニウム、または硫酸アンモニウム及びアンモニ
アの溶液を添加混練して加熱処理した後、さらに硫酸第
一鉄の溶液を添加混練して加熱処理することを特徴とす
る、重金属等含有灰の処理方法。3. A method of adding and kneading ammonium sulfate or a solution of ammonium sulfate and ammonia to sewage sludge incineration ash containing heavy metals and the like, heating the mixture, and further adding and kneading a solution of ferrous sulfate and heating. A method for treating ash containing heavy metals and the like, characterized in that:
酸アンモニウム、または硫酸アンモニウム及びアンモニ
アの溶液を添加混練して加熱処理した後、さらに硫酸第
一鉄の溶液を添加混練して、放置した後加熱処理するこ
とを特徴とする、重金属等含有灰の処理方法。4. After adding and kneading ammonium sulfate or a solution of ammonium sulfate and ammonia to sewage sludge incineration ash containing heavy metals and the like, heating and adding, further adding and kneading a solution of ferrous sulfate, and allowing the mixture to stand. A method for treating ash containing heavy metals or the like, characterized by performing a heat treatment.
とする、請求項２または４記載の重金属等含有灰の処理
方法。5. The method for treating ash containing heavy metals and the like according to claim 2, wherein the period of leaving is one day or more.
される硫酸アンモニウム、または硫酸アンモニウム及び
アンモニアの割合が焼却灰の0.5重量％以上であること
を特徴とする、請求項３または４記載の重金属等含有灰
の処理方法。6. The heavy metal according to claim 3, wherein ammonium sulfate added to the sewage sludge incineration ash containing heavy metals or the like, or the proportion of ammonium sulfate and ammonia is 0.5% by weight or more of the incineration ash. How to treat ash and other ash.
される硫酸第一鉄の割合が、無水物としての添加割合で
焼却灰の0.5重量％以上であることを特徴とする、請求
項１〜６までのいずれかに記載の重金属等含有灰の処理
方法。7. The ratio of ferrous sulfate added to sewage sludge incineration ash containing heavy metals and the like is 0.5% by weight or more of incineration ash as an anhydride. 7. The method for treating ash containing heavy metals and the like according to any one of 1 to 6.
を特徴とする、請求項１〜７までのいずれかに記載の重
金属等含有灰の処理方法。8. The method for treating ash containing heavy metals and the like according to claim 1, wherein the temperature of the heat treatment is 50 to 450 ° C.
水汚泥焼却灰に添加、混練、もしくは混練及び放置し
て、加熱処理した後にpH調整剤を添加することを特徴と
する、請求項１〜８までのいずれかに記載の重金属等含
有灰の処理方法。9. A method of adding a ferrous sulfate solution to sewage sludge incineration ash containing heavy metals and the like, kneading or kneading and leaving the mixture, and after heating, adding a pH adjuster. Item 10. The method for treating ash containing heavy metals or the like according to any one of Items 1 to 8.
のであることを特徴とする、請求項９記載の重金属等含
有灰の処理方法。10. The method for treating ash containing heavy metals and the like according to claim 9, wherein the pH adjuster can adjust the pH to about 5 or more.
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|---|---|---|---|
| JP2001115471A JP2002001273A (en) | 2000-04-18 | 2001-04-13 | Method for treating ash containing heavy metals or the like |
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|---|---|---|---|
| JP2000-116167 | 2000-04-18 | ||
| JP2000116167 | 2000-04-18 | ||
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| Publication Number | Publication Date |
|---|---|
| JP2002001273A true JP2002001273A (en) | 2002-01-08 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007268339A (en) * | 2006-03-30 | 2007-10-18 | Actree Corp | Method for burning heavy metal containing raw material |
| JP7009008B1 (en) | 2021-10-20 | 2022-01-25 | 学校法人福岡工業大学 | How to treat sewage sludge incinerator ash |
-
2001
- 2001-04-13 JP JP2001115471A patent/JP2002001273A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007268339A (en) * | 2006-03-30 | 2007-10-18 | Actree Corp | Method for burning heavy metal containing raw material |
| JP7009008B1 (en) | 2021-10-20 | 2022-01-25 | 学校法人福岡工業大学 | How to treat sewage sludge incinerator ash |
| JP2023061513A (en) * | 2021-10-20 | 2023-05-02 | 学校法人福岡工業大学 | Method for treating sewage sludge incineration ashes |
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